Initial implementation of diff rename detection

This implements the basis for diff rename and copy detection,
although it is based on simple SHA comparison right now instead
of using a matching algortihm.  Just as `git_diff_merge` can be
used as a post-pass on diffs to emulate certain command line
behaviors, there is a new API `git_diff_detect` which will
update a diff list in-place, adjusting some deltas to RENAMED
or COPIED state (and also, eventually, splitting MODIFIED deltas
where the change is too large into DELETED/ADDED pairs).

This also adds a new test repo that will hold rename/copy/split
scenarios.  Right now, it just has exact-match rename and copy,
but the tests are written to use tree diffs, so we should be able
to add new test scenarios easily without breaking tests.

1 files changed, 37 insertions, 39 deletions

diff --git a/tests-clar/diff/blob.c b/tests-clar/diff/blob.c
index d5cf41e99..0a37e829d 100644
--- a/tests-clar/diff/blob.c
+++ b/tests-clar/diff/blob.c
@@ -59,8 +59,8 @@ void test_diff_blob__can_compare_text_blobs(void)
 		a, b, &opts, &expected, diff_file_fn, diff_hunk_fn, diff_line_fn));
 
 	cl_assert_equal_i(1, expected.files);
-	cl_assert_equal_i(1, expected.file_mods);
-	cl_assert(expected.at_least_one_of_them_is_binary == false);
+	cl_assert_equal_i(1, expected.file_status[GIT_DELTA_MODIFIED]);
+	cl_assert_equal_i(0, expected.files_binary);
 
 	cl_assert_equal_i(1, expected.hunks);
 	cl_assert_equal_i(6, expected.lines);
@@ -74,8 +74,8 @@ void test_diff_blob__can_compare_text_blobs(void)
 		b, c, &opts, &expected, diff_file_fn, diff_hunk_fn, diff_line_fn));
 
 	cl_assert_equal_i(1, expected.files);
-	cl_assert_equal_i(1, expected.file_mods);
-	cl_assert(expected.at_least_one_of_them_is_binary == false);
+	cl_assert_equal_i(1, expected.file_status[GIT_DELTA_MODIFIED]);
+	cl_assert_equal_i(0, expected.files_binary);
 
 	cl_assert_equal_i(1, expected.hunks);
 	cl_assert_equal_i(15, expected.lines);
@@ -89,8 +89,8 @@ void test_diff_blob__can_compare_text_blobs(void)
 		a, c, &opts, &expected, diff_file_fn, diff_hunk_fn, diff_line_fn));
 
 	cl_assert_equal_i(1, expected.files);
-	cl_assert_equal_i(1, expected.file_mods);
-	cl_assert(expected.at_least_one_of_them_is_binary == false);
+	cl_assert_equal_i(1, expected.file_status[GIT_DELTA_MODIFIED]);
+	cl_assert_equal_i(0, expected.files_binary);
 
 	cl_assert_equal_i(1, expected.hunks);
 	cl_assert_equal_i(13, expected.lines);
@@ -103,8 +103,8 @@ void test_diff_blob__can_compare_text_blobs(void)
 		c, d, &opts, &expected, diff_file_fn, diff_hunk_fn, diff_line_fn));
 
 	cl_assert_equal_i(1, expected.files);
-	cl_assert_equal_i(1, expected.file_mods);
-	cl_assert(expected.at_least_one_of_them_is_binary == false);
+	cl_assert_equal_i(1, expected.file_status[GIT_DELTA_MODIFIED]);
+	cl_assert_equal_i(0, expected.files_binary);
 
 	cl_assert_equal_i(2, expected.hunks);
 	cl_assert_equal_i(14, expected.lines);
@@ -125,8 +125,8 @@ void test_diff_blob__can_compare_against_null_blobs(void)
 		d, e, &opts, &expected, diff_file_fn, diff_hunk_fn, diff_line_fn));
 
 	cl_assert_equal_i(1, expected.files);
-	cl_assert_equal_i(1, expected.file_dels);
-	cl_assert(expected.at_least_one_of_them_is_binary == false);
+	cl_assert_equal_i(1, expected.file_status[GIT_DELTA_DELETED]);
+	cl_assert_equal_i(0, expected.files_binary);
 
 	cl_assert_equal_i(1, expected.hunks);
 	cl_assert_equal_i(14, expected.hunk_old_lines);
@@ -140,8 +140,8 @@ void test_diff_blob__can_compare_against_null_blobs(void)
 		d, e, &opts, &expected, diff_file_fn, diff_hunk_fn, diff_line_fn));
 
 	cl_assert_equal_i(1, expected.files);
-	cl_assert_equal_i(1, expected.file_adds);
-	cl_assert(expected.at_least_one_of_them_is_binary == false);
+	cl_assert_equal_i(1, expected.file_status[GIT_DELTA_ADDED]);
+	cl_assert_equal_i(0, expected.files_binary);
 
 	cl_assert_equal_i(1, expected.hunks);
 	cl_assert_equal_i(14, expected.hunk_new_lines);
@@ -154,10 +154,9 @@ void test_diff_blob__can_compare_against_null_blobs(void)
 	cl_git_pass(git_diff_blobs(
 		alien, NULL, &opts, &expected, diff_file_fn, diff_hunk_fn, diff_line_fn));
 
-	cl_assert(expected.at_least_one_of_them_is_binary == true);
-
 	cl_assert_equal_i(1, expected.files);
-	cl_assert_equal_i(1, expected.file_dels);
+	cl_assert_equal_i(1, expected.files_binary);
+	cl_assert_equal_i(1, expected.file_status[GIT_DELTA_DELETED]);
 	cl_assert_equal_i(0, expected.hunks);
 	cl_assert_equal_i(0, expected.lines);
 
@@ -166,20 +165,19 @@ void test_diff_blob__can_compare_against_null_blobs(void)
 	cl_git_pass(git_diff_blobs(
 		NULL, alien, &opts, &expected, diff_file_fn, diff_hunk_fn, diff_line_fn));
 
-	cl_assert(expected.at_least_one_of_them_is_binary == true);
-
 	cl_assert_equal_i(1, expected.files);
-	cl_assert_equal_i(1, expected.file_adds);
+	cl_assert_equal_i(1, expected.files_binary);
+	cl_assert_equal_i(1, expected.file_status[GIT_DELTA_ADDED]);
 	cl_assert_equal_i(0, expected.hunks);
 	cl_assert_equal_i(0, expected.lines);
 }
 
-static void assert_identical_blobs_comparison(diff_expects expected)
+static void assert_identical_blobs_comparison(diff_expects *expected)
 {
-	cl_assert_equal_i(1, expected.files);
-	cl_assert_equal_i(1, expected.file_unmodified);
-	cl_assert_equal_i(0, expected.hunks);
-	cl_assert_equal_i(0, expected.lines);
+	cl_assert_equal_i(1, expected->files);
+	cl_assert_equal_i(1, expected->file_status[GIT_DELTA_UNMODIFIED]);
+	cl_assert_equal_i(0, expected->hunks);
+	cl_assert_equal_i(0, expected->lines);
 }
 
 void test_diff_blob__can_compare_identical_blobs(void)
@@ -187,32 +185,32 @@ void test_diff_blob__can_compare_identical_blobs(void)
 	cl_git_pass(git_diff_blobs(
 		d, d, &opts, &expected, diff_file_fn, diff_hunk_fn, diff_line_fn));
 
-	cl_assert(expected.at_least_one_of_them_is_binary == false);
-	assert_identical_blobs_comparison(expected);
+	cl_assert_equal_i(0, expected.files_binary);
+	assert_identical_blobs_comparison(&expected);
 
 	memset(&expected, 0, sizeof(expected));
 	cl_git_pass(git_diff_blobs(
 		NULL, NULL, &opts, &expected, diff_file_fn, diff_hunk_fn, diff_line_fn));
 
-	cl_assert(expected.at_least_one_of_them_is_binary == false);
-	assert_identical_blobs_comparison(expected);
+	cl_assert_equal_i(0, expected.files_binary);
+	assert_identical_blobs_comparison(&expected);
 
 	memset(&expected, 0, sizeof(expected));
 	cl_git_pass(git_diff_blobs(
 		alien, alien, &opts, &expected, diff_file_fn, diff_hunk_fn, diff_line_fn));
 
-	cl_assert(expected.at_least_one_of_them_is_binary == true);
-	assert_identical_blobs_comparison(expected);
+	cl_assert(expected.files_binary > 0);
+	assert_identical_blobs_comparison(&expected);
 }
 
-static void assert_binary_blobs_comparison(diff_expects expected)
+static void assert_binary_blobs_comparison(diff_expects *expected)
 {
-	cl_assert(expected.at_least_one_of_them_is_binary == true);
+	cl_assert(expected->files_binary > 0);
 
-	cl_assert_equal_i(1, expected.files);
-	cl_assert_equal_i(1, expected.file_mods);
-	cl_assert_equal_i(0, expected.hunks);
-	cl_assert_equal_i(0, expected.lines);
+	cl_assert_equal_i(1, expected->files);
+	cl_assert_equal_i(1, expected->file_status[GIT_DELTA_MODIFIED]);
+	cl_assert_equal_i(0, expected->hunks);
+	cl_assert_equal_i(0, expected->lines);
 }
 
 void test_diff_blob__can_compare_two_binary_blobs(void)
@@ -227,14 +225,14 @@ void test_diff_blob__can_compare_two_binary_blobs(void)
 	cl_git_pass(git_diff_blobs(
 		alien, heart, &opts, &expected, diff_file_fn, diff_hunk_fn, diff_line_fn));
 
-	assert_binary_blobs_comparison(expected);
+	assert_binary_blobs_comparison(&expected);
 
 	memset(&expected, 0, sizeof(expected));
 
 	cl_git_pass(git_diff_blobs(
 		heart, alien, &opts, &expected, diff_file_fn, diff_hunk_fn, diff_line_fn));
 
-	assert_binary_blobs_comparison(expected);
+	assert_binary_blobs_comparison(&expected);
 
 	git_blob_free(heart);
 }
@@ -244,14 +242,14 @@ void test_diff_blob__can_compare_a_binary_blob_and_a_text_blob(void)
 	cl_git_pass(git_diff_blobs(
 		alien, d, &opts, &expected, diff_file_fn, diff_hunk_fn, diff_line_fn));
 
-	assert_binary_blobs_comparison(expected);
+	assert_binary_blobs_comparison(&expected);
 
 	memset(&expected, 0, sizeof(expected));
 
 	cl_git_pass(git_diff_blobs(
 		d, alien, &opts, &expected, diff_file_fn, diff_hunk_fn, diff_line_fn));
 
-	assert_binary_blobs_comparison(expected);
+	assert_binary_blobs_comparison(&expected);
 }
 
 /*